%This m-script shows a simple simulation for the crank-slider mechanism for
% the crank shaft-piston mechanism
% l = rod length (distance between piston pin and crank pin)
% r = crank radius (distance between crank pin and crank center, i.e. half stroke)
% A = crank angle (from cylinder bore centerline at TDC)
% x = piston pin position (upward from crank center along cylinder bore centerline)
% Check http://en.wikipedia.org/wiki/Piston_motion_equations for more
% details
%Written by: Nassim Khaled-February 2010
%The crank-slider mechanism scretch
% P
% o
% o
% o
% o N
% *
% *
% *
% O
% O [0,0] is the pivot of the crank shaft
l=30;
r=15;
X=[0 0 0];
Y=[0 r r+l];
X_Piston=[-7 7 7 -7 -7];
Y_Piston=[l-5 l-5 l+5 l+5 l-5];
h = plot(X,Y,'LineWidth',4,'XDataSource','X','YDataSource','Y');
axis([-1.1*r 1.1*r -1.5*r 1.5*r+l]);
set(gca,'DataAspectRatio',[1 1 1])
grid on
hold('all')
g = plot(X_Piston,Y_Piston,'r','LineWidth',4,'XDataSource','X_Piston','YDataSource','Y_Piston');
angle=0:0.01:2*pi;
x_circle=r.*cos(angle);
y_circle=r.*sin(angle);
i = plot(x_circle,y_circle,'LineWidth',4)
for A=0:0.08:4*pi
x=r*cos(A)+sqrt(l^2-r^2*sin(A)^2);
N=[r*sin(A) r*cos(A)];
P=[0 x];
X=[0 r*sin(A) 0];
Y=[0 r*cos(A) x];
Y_Piston=[x-5 x-5 x+5 x+5 x-5];
refreshdata(h,'caller')
refreshdata(g,'caller')
refreshdata(i,'caller')
drawnow
pause(.1)
end
